Research Reports - Brain structure and function associated with a history of sport concussion

There is growing concern about the potential long-term consequences of sport
concussion for young, currently active athletes. However, there remains limited
information about brain abnormalities associated with a history of concussion and
how they relate to clinical factors. In this study, advanced MRI was used to
comprehensively describe abnormalities in brain structure and function associated
with a history of sport concussion. Forty-three athletes (21 male, 22 female)
were recruited from interuniversity teams at the beginning of the season,
including 21 with a history of concussion and 22 without prior concussion; both
groups also contained a balanced sample of contact and noncontact sports.
Multi-modal MRI was used to evaluate abnormalities in brain structure and
function. Athletes with a history of concussion showed frontal decreases in brain
volume and blood flow. However, they also demonstrated increased posterior
cortical volume and elevated markers of white matter microstructure. A greater
number of prior concussions was associated with more extensive decreases in
cerebral blood flow and insular volume, whereas recovery time from most recent
concussion was correlated with reduced frontotemporal volume. White matter showed
limited correlations with clinical factors, predominantly in the anterior corona
radiata. This study provides the first evidence of the long-term effects of
concussion on gray matter volume, blood flow, and white matter microstructure
within a single athlete cohort. This was examined for a mixture of male and
female athletes in both contact and noncontact sports, demonstrating the
relevance of these findings for the overall sporting community.